Trousers need openings made we hear (8)
I believe the answer is:
breeches
'trousers' is the definition.
(breeches is a kind of trousers)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for breeches that I've seen before include "Short trousers" , "Trousers reaching to just below the knee" , "Trousers ending just below the knee" , "Riding trousers" , "Pants" .)